The present invention relates to a level measuring device, and more particularly a device for measuring liquid levels in tanks, such as storage tanks, liquid dispensing tanks and the like.
Many industries require storage of liquids and viscous liquids in tanks during processing and dispensing. The oilfield industry uses drilling mud for a variety of onshore and offshore operations. The drill muds are usually stored in special tanks having a top opening for input of the drill mud and an outlet in the bottom of the tank for dispensing of the mud as needed.
The viscosity of the drill mud and the chemical composition thereof play an important role in the success of the drilling and circulation operations. Some of the factors that need to be continuously monitored during dispensing is the viscosity of the mud, which may be lighter or heavier, depending on the strata, rock formations, and other conditions in a well bore. Some of the additives are relatively expensive and are added in small amounts. Other additives, such as synthetic oils may be added in larger amounts to facilitate drilling operations.
Mud engineers and workers carefully monitor the content of the circulation mud and the level of it in a mud tank. The mud tanks are usually made of steel. Sometimes expensive level measuring devices are used. More often, a mud engineer climbs to the top of the tank and peers into the dark interior of the dispensing tank to roughly estimate whether the mud is of the right viscosity and whether any additions are required.
Another method of making a rough estimate is to tap the side of the tank and try to guess by the reverberating sound how much mud is left in the mud tank. The mud engineers often times have to guess how much mud is left in the stainless steel tank because there is no measuring indicia and no windows through which one can see the level of liquid in the tank.
Sometimes the mud engineer has to supervise a number of such tanks and, in inclement weather, climbing up and down to reach the deck where the tanks are positioned becomes a serious task, especially due to the voluminous size of the tanks and difficulty of visual inspection.
The present invention contemplates elimination of drawbacks associated with the current methods of determining the level in the mud tank and provision of an inexpensive, easy-to use device for measuring the level of contents in a tank.
It is, therefore, an object of the present invention to provide a device for measuring a level of liquid in a storage or dispensing tank.
It is another object of the present invention to provide a level-measuring device that would allow an operator to determine the level of liquid left in the tank by visual observation from the exterior of the tank.
It is a further object of the present invention to provide a level-measuring device that is particularly adapted for use with mud tanks.
These and other objects of the present invention are achieved through a provision of an apparatus for measuring the level of liquid, which comprises an elongated hollow body having a floating member secured on its lower end. The elongated body carries a coupler, within which the body freely slides. A lower part of the coupler has inner threads that are adapted to engage with the threads of a nipple secured on the top of the tank. The nipple has exterior threads; it is usually covered with a lid, or cap when the liquid is stored or dispensed. The outlet port of the tank is on the bottom of the tank.
An upper portion of the body is provided with a top cap. An upper part of the coupler contacts a sliding stop that prevents the coupler from disengaging from the body. The stop has an inner opening with a diameter smaller than the size of the top cap.
The level measuring device is lowered into the tank with liquid such that the float member floats on top of the liquid. The coupler is threadably engaged with the threads of the nipple after the lid has been removed from the tank. The body, which has a length approximating the depth of the tank, gradually lowers into the tank by sliding through the stationary coupler. The body descends into the tank as the level of liquid in the tank decreases.
The exterior surface of the body is provided with measuring indicia to allow an operator to visually observe the decreasing level of liquid in the tank from the outside of the tank. If the level decreases too slow an operator may have to adjust the viscosity of the liquid. Conversely, if the tank empties too fast, the operator may need to add solid additives to the mixture in the tank. If the liquid stops flowing, there may be an obstruction in the line that needs to be attended to.
The device of the present invention is easy to operate and inexpensive to manufacture. It does not require any modifications in the existing tank structure, instead capable of accommodating all types of storage and dispensing tanks.